3. You must have unlocked bootloader of your device. You can do so from here.

II. Installing ClockworkMod Recovery on the Sony Xperia Z

1. Download and place both the Advanced Stock Kernel onto your Desktop.

2. Extract files from the Fastboot archive to your Desktop.

3. Turn ON the USB debugging option on your device by going to Menu>>Settings>>Developer options>>USB debugging.

4. Once enabled, connect your device to your PC via USB cable.

5. Launch a Command Prompt Window on the Desktop of your PC. To do so, press and hold the Shift button on your keyboard and right-click on any blank area on the screen, then choose Open command window here.

6. Type in following command into the Command Prompt Window:

adb reboot bootloader

7. Your device will reboot into the bootloader mode.

8. Once inside bootloader mode, enter the following command into Command Prompt. Make sure to replace kernel.img with the actual name of the Image you downloaded.

fastboot flash boot kernel.img

9. Once the file’s flashed, reboot your device.

10. And you’re all set!

You’ve successfully installed ClockworkMod Recovery on your Xperia ZL and now comes the time to flash some ROMs.